ASU experts weigh in on discovery of warm, rocky 'Earth-like' planets

Liquid water, an atmosphere and a magnetic field could make a planet habitable.

February 22, 2017

The discovery of seven warm, rocky “Earth-like” planets orbiting a star 39 light-years away has created new opportunities for science, according to the lead researcher of the NASA study published in the journal Nature on Wednesday.

“Before this, if you wanted to study terrestrial planets, we had only four of them and they were all in our solar system,” exoplanetary scientist Michael Gillon told the Washington Post. “Now we have seven Earth-sized planets to expand our understanding. Yes, we have the possibility to find water and life. But even if we don't, whatever we find will be super interesting.”

ASU Now tapped associate professor Jennifer Patience and assistant professor Evgenya Shkolnik of Arizona State University's School of Earth and Space Exploration — experts on exoplanetsAn exoplanet is a planet that orbits a star outside Earth’s solar system. and habitable zonesA habitable zone is a region of space where conditions are best for life to form as on Earth. — to explain what we could find, how we could find it and what it could teach us.

Question: What could we possibly find on these planets?

Evgenya Shkolnik

Shkolnik: There are a few things we could find that I’m curious about. One is do they have atmospheres? There’s some potential that their atmospheres might be blown off by the star’s activities. Once that’s determined, I want to know what is in those atmospheres, which involves the detection of biosignatures — indications of life on planets.

But knowing anything about them is valuable, even if they don’t have life. Everyone wants to know how common is life? If we find out that none of these planets have life, which I think is highly unlikely, it tells us something about how unique life is on Earth. The question now is how are we going to detect life on these planets? There are opportunities for false-positive and false-negative detections of life. So how do we say for sure?

Q: So how do we detect life and/or biosignatures on these planets?

Jennifer Patience

Patience: The newly discovered planets pass in front of the host star, and with sensitive measurements from telescopes it is possible to study the starlight passing through the atmosphere of the planet to learn about the composition of the atmosphere. Several possibilities include an atmosphere largely made up of hydrogen and helium, or containing molecules such as water and carbon monoxide. The measurements can be made with telescopes in space and on the ground, and the different colors of light are important to investigate different aspects of the atmosphere.

Shkolnik: You can look at different wavelengths of light to get the biosignatures that indicate oxygen and ozone and methane, which are the kind of biosignatures that exist in Earth’s atmosphere. You’d need to use infrared, like the James Webb Space Telescope will do. This solar system will most certainly be observed with JWST. We’ll receive some information about the planets’ atmospheres, assuming they have atmospheres, through that.

At the NASA press conference (Wednesday), one of the researchers involved in the discovery received a question from a reporter about whether or not SETISETI, or the search for extraterrestrial intelligence, is a collective term for scientific searches for intelligent extraterrestrial life; for example, monitoring electromagnetic radiation for signs of transmissions from civilizations on other worlds., which observes radio wavelengths from space, has observed these planets. As far as he knows, SETI has observed the planets but has not observed radio intelligence. So that’s one way of detecting life, but that’s a way to detect intelligent life. The first way to determine if there is life on a planet is to look for biosignatures; there can be biosignatures that indicate life is present but not necessarily intelligent.

Q: What are some of the challenges to finding life on these planets?

Shkolnik: We need to understand what the star is doing because all of the light that we see is the starlight as it passes through the atmosphere of the planet. It’s as if the planet is backlit by the star, so you see the signatures — the fingerprints of these molecules of interest — imposed on the stellar light, which can change how they are interpreted. So one of the issues is we need to understand the star light well.

Another challenge is that it’s possible that stellar photons are producing haze or clouds on planets, making it hard to determine its biosignatures. And, of course, there’s the challenge that life there may be subsurface, so wouldn’t be detectable by observing the surface of the planet.

Q: Do we even know what conditions make for a habitable planet?

Patience: There are a range of factors that are important, including the temperature and radiation environment of the planet. A key requirement is a temperature that would allow liquid water to be present. Water is an important factor for life, so a detection of water would be an important step in the exploration of these planets, though water alone would not determine if there is life present on an exoplanet.

Shkolnik: It’s hard to create a set list because the conditions of Earth are the only ones we know about. It’s the only place we know about with life, at the moment. So we have a very Earth-centric understanding of what it takes for a planet to be habitable. But we have some basic conditions.

One of the first conditions that defines a habitable planet is that the surface of the planet receives enough radiation from the sun to be the right temperature to sustain liquid water. Then there’s Earth’s magnetic field, which shields the Earth from high-energy particles from the sun that could potentially strip away our atmosphere, exposing Earth’s surface to space weather elements. So you need liquid water, you need an atmosphere and you need a magnetic field.

Q: What can we learn from studying these new planets?

Shkolnik: I think it will add to our body of knowledge of how common Earth-sized planets are, and particularly Earth-sized size planets in habitable zones.

It’s going to affect everyone in our field’s next telescope proposal. Everyone will want to use Hubble, if they’re not already. Everyone will want to use the James Webb Space Telescope; everyone will be proposing new research to use it. I think there’s going to be many papers coming out pretty soon, like there were after Proxima b back in August. There’ll be the same wave of theory and enthusiasm.

Q: What is most exciting about this discovery?

Shkolnik: I think it’s going to be the first of many discoveries like it. With anything in astronomy, if you find one, there’s probably many more. I think it confirms what we already learned from the Kepler space mission, that planets around these low-mass stars are ubiquitous, including habitable-zone planets. So this is really just the beginning.

Patience: A really exciting aspect of this discovery is the fact that there are multiple Earth-sized planets in the habitable zone, compared to other exoplanet systems that have only one or no planets in the habitable zone. Thousands of exoplanets are known, but only a much smaller number are in the habitable zones of their host stars, and this is the only system with several Earth-sized planets in the habitable zone.

Top photo: Artist illustration of the possible surface of TRAPPIST-1f, one of the newly discovered planets in the TRAPPIST-1 system. Scientists using the Spitzer Space Telescope and ground-based telescopes have discovered that there are seven Earth-size planets in the system. Credit: NASA/JPL-Caltech

Emma Greguska

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As the federal government wrangles over the rights of transgender students, an Arizona State University expert says that politics aside, schools can still create an affirming environment for those children.President Donald Trump revoked anti-discrimination protections for transgender students on Wednesday; some news outlets had reported disagreement among top federal officials on the rollback.“I...

Politics aside, ASU expert says schools can help transgender students

ASU expert teaches schools how to be affirming for transgender students.

February 22, 2017

Camellia Bellis of T. Sanford Denny School of Social and Family Dynamics says schools can set non-discrimination policies

As the federal government wrangles over the rights of transgender students, an Arizona State University expert says that politics aside, schools can still create an affirming environment for those children.

President Donald Trump revoked anti-discrimination protections for transgender students on Wednesday; some news outlets had reported disagreement among top federal officials on the rollback.

“I think this step by the administration serves as a blow to transgender youth, but we know that schools and districts around the country still have a moral and ethical and legal responsibility to make sure all students feel safe and free of discrimination and harassment,” said Camellia Bellis, who has worked as an advocate for transgender students and their families.

Last May, the U.S. Education and Justice departments said that transgender students should be allowed to use facilities such as bathrooms and locker rooms consistent with their gender identity. Immediately after that ruling, Arizona joined several other states in a lawsuit challenging that interpretation.

Bellis, a program manager, developed a transgender education program that is being offered to K–12 teachers by Project Connect, part of the T. Sanford Denny School of Social and Family Dynamics at ASU. The workshops trains teachers, administrators, nurses, counselors and other educators in how to create a welcoming atmosphere that helps transgender students learn.

Transgender people have a gender identity, or gender expression, that differs from their assigned sex.

Bellis answered some questions for ASU Now:

Question: How will a rollback on the federal guidelines affect schools?

Answer: It might seem a bit confusing to some schools or districts — what, specifically are they supposed to do? We know that Title IXTitle IX is the federal law prohibiting sex-based discrimination in education. and the U.S. Constitution protect transgender students from discrimination. They just don’t have that federal backing right now, and it’s sad because it sends a message to transgender youth in this country that “you don’t matter to the federal government.” And that’s a harmful message to send.

There are no state protections in Arizona for LGBT students, so it really is dependent on districts and schools to have those policies.

We won’t know much more legally until the arguments in front of the Supreme CourtThe Supreme Court is set to hear oral arguments on March 28 in the case of a transgender teenager from Virginia, Gavin Grimm, who sued for the right to use the boys’ bathroom. at the end of March.

Q: How many transgender students are there?

A: The Williams InstituteThe Williams Institute is a think tank at the University of California Los Angeles School of Law. came out last year and said it can be anywhere from 0.3 to 0.8 percent of the population. Those of us who work with trans youths in school think it’s about 1 percent of the population. So if you have 500 students in a school, you’ll have about five trans students. Whether they’re ‘out’ or not is another story.

When we hear a school say, “We don’t have any trans students,” that’s not true. They just don’t know about them.

Q: How can schools affirm transgender students?

A: They can take proactive steps, making sure they have nondiscrimination policies that protect them, specifically stating that they’re allowed to use the bathroom of the gender they identify with, and (the schools) will use the asserted pronoun they identify with. They should have conversations with staff. Some have called it a “gender-support plan,” where it spells out exactly what that district’s stand is on bathrooms, locker rooms, sports teams, physical education, how do we keep their files confidential, make sure their (previous) name isn’t launched out there by a substitute teacher?

We recently did a training for high school nurses, and most them didn’t know what their school’s policy was. Can transgender students use the bathroom? They didn’t know.

Taking a stance says, “The federal government may not feel that this vulnerable population needs to be protected, but in this school we will make sure you’re safe and affirmed and we know that when you feel affirmed, you can learn.”